Western Antartica’s immense glaciers are melting fast and giving up ice to the sea at a rate that is considered already past “the point of no return," according to recent research work done by two different groups of scientists.

The resulting scenario is compelling: an increase in the world sea levels of 4 feet or more in the next centuries, according to findings announced Monday by scientists from the University of Washington, the University of California-Irvine and the Jet Propulsion Laboratory at NASA.

"It truly is a startlingly disturbing situation," says Pennsylvania State University glaciologist Sridhar Anandakrishnan, who was not associated with any of the research studies. "This is a big part of West Antarctica, and it appears to have been pushed violently over the edge."

The researchers claim the glaciers are most certainly bound to be lost.

One study confirms that a river of ice named Thwaites Glacier is possibly starting to collapse and that complete collapse is likely to occur.

A second research illustrates that six glaciers are giving up ice into the sea at an ever-increasing rate. At that rate, there will be a 4-feet increase in the sea-level, states study author Eric Rignot, a glaciologist at the University of California-Irvine, and NASA's Jet Propulsion Laboratory.

"The ice retreat in that area is inescapable," Rignot said at a briefing Monday, adding that the glaciers have gone beyond “the point-of-no-return."

Rignot and his group utilized data from satellites and aircraft to monitor changes in six West Antarctic glaciers and the terrain beneath these massive ice floes. The data gathered confirm that the glaciers are spreading out and decreasing in thickness and volume. They are also moving faster from the continent's center toward the sea, giving up more volumes of ice into the ocean than before and raising sea levels as a result.

Simultaneously, the area of each glacier protruding into the sea is being melted underwater by the surrounding warm ocean water. This results in the vicious process of increased thinning and more rapid flow, and the local terrain provides no barrier to the glaciers' retreat, the researchers announce in the next issue of Geophysical Research Letters.

An article in this week's Science says the Thwaites Glacier is predicted to collapse completely in 200 years. The paper, however, does not specify the height of sea-level increase associated with Thwaites' disappearance.